BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Muhlenbergia montana | Mountain Muhly 



GENERAL BOTANICAL CHARACTERISTICS : 
Mountain muhly is a native, perennial, warm-season bunchgrass [6,23].
Culms are branched at the base [82] and densely tufted [40,60]; they are
usually erect and 4 to 32 inches (10-80 cm) tall [16,34,40,82].  Leaves
are mostly basal and densely clustered; there are also some culm leaves
[16,82].  Leaf blades are 2 to 10 inches (5-25 cm) long [16,34,82].
Leaf sheaths become papery and loose from the culm [38] and are
persistent, often becoming flattened with age [82].  The inflorescence
is a narrow, oblong, erect or nodding panicle 2 to 6 inches (5-15 cm)
long [16,34,40]; the branches are 0.4 to 3.5 inches (1-9 cm) long, and
erect to moderately spreading [82].  Spikelets are one flowered [16].
Lemma awns are 0.24 to 0.79 inch (6-20 mm) long [16,34,40].  The fruit
is a caryopsis [34].

Mountain muhly has fibrous roots [10].  In a variety of soils, 15
percent of mountain muhly roots were in the first 3 feet (.91 m) of
soil, and 58 percent were in the first 6 feet (1.83 m).  The deepest
roots were 9 feet deep (2.74 m) [29].


RAUNKIAER LIFE FORM : 
   Hemicryptophyte


REGENERATION PROCESSES : 
Mountain muhly reproduces by seed [16].  It can also reproduce
vegetatively by tillering, and sometimes spreads slowly by this method
[80].

On western Colorado ponderosa pine ranges, mountain muhly seedstalk
production is abundant in normal growing seasons [15].

In central Arizona mountain muhly sometimes retains its seeds into the
winter months [80].


SITE CHARACTERISTICS : 
Mountain muhly is found in dry to moist sites [23,82], but it requires
excellent drainage [40].  It is found in grassy parklands, on slopes and
foothills [16,20,82], on rocky, dry hillsides [24,25,34], and in
canyons and on mesas [34,38,46].  In Arizona it is the principal grass
on dry forested ranges between meadows [44].

Mountain muhly usually occurs on coarse to loamy soils, although it
sometimes occurs on clays.  In Arizona mountain muhly grows on stony
clayey loam [4], sandy loam developed from basaltic parent material
[27], gravelly loam with a broken surface of volcanic rock, gravelly
sandy loams of both limestone and sandstone origin, and red clay [6].
In California mountain muhly grows on granitic rock outcrops [40].  In
Colorado mountain muhly grows on gravelly sandy loam, stony loam
developed from limestone, fine loose sand from disintegrating sandstone,
[10], and infertile, coarse-textured soil with little profile
development [33].  In Utah mountain muhly grows on basaltic stony loams
[63].  Mountain muhly grows poorly on acidic and saline soils [23].

In central Arizona mountain muhly grows where precipitation occurs
mainly during winter and late summer [4].  Annual maximum precipitation
occurs from July through September; a secondary period occurs from
December through March.  Fall and late spring months are usually arid
[20].  Annual precipitation ranges from 17 to 25 inches (430-640 mm).
In Colorado about two-thirds of the annual precipitation, which averages
15.9 inches (404 mm), falls during the April through September growing
season [33].

Mountain muhly is reported at the following elevations:

                      Feet            Meters

Arizona           4,000-9,203       1,219-2,805    [5,12,20,27,46]
California        4,500-11,220      1,372-3,420    [40,60]
Colorado          5,500-10,400      1,676-3,170    [10,23,34]
Montana           2,650-6,000         808-1,829    [36,74]
New Mexico        5,387-11,100      1,642-3,383    [1,29,56]
Texas                 7,500             2,286      [41]
Utah              6,004-10,810      1,830-3,295    [82,84]
Wyoming               7,300             2,225      [23]


SUCCESSIONAL STATUS : 
Mountain muhly occurs in seral and climax communities.  On ponderosa
pine/bunchgrass ranges of the central Rocky Mountains, the Arizona
fescue-mountain muhly stage is seral to ponderosa pine-fir forest [18].
In ponderosa pine/bunchgrass forests of Arizona and New Mexico, mountain
muhly declines in the successional sequence that follows complete fire
suppression [58].

Mountain muhly grows best in full sun [40].  In northern Arizona
mountain muhly declines as shade from ponderosa pine increases [6].  In
central Colorado mountain muhly declines with litter accumulation and
increased shading by young trees [33].

In parklike stands and openings in ponderosa pine forests of Arizona,
mountain muhly and other bunchgrasses develop into dense, exclusive
communities that resist penetration by other species, including
ponderosa pine [71].


SEASONAL DEVELOPMENT : 
Mountain muhly grows during the spring and summer months [38].  Mountain
muhly becomes semidormant if there is midsummer drought [64].  In
northern Arizona the start of mountain muhly growth is related to the
time of spring thaw, which begins when maximum air temperatures attain
50 degrees Fahrenheit (10 deg C).  This temperature is usually achieved
about the beginning of March [65].

On northern Arizona ponderosa pine/bunchgrass range, mountain muhly was
measured during the snow-free months from 1963 through 1965.  Overwinter
green height of mountain muhly was less than 1.3 inches (3.3 cm).
Mountain muhly peak growth was during July and August; extent of growth
appeared to be closely related to precipitation during those months.
Mountain muhly ceased growing during September.  Phenological
development of mountain muhly was as follows [65]:

                        1963          1964          1965

    Heads showing      Sept. 5       Sept. 4       Aug. 15
    Flowers in bloom   Sept. 25      Sept. 24      Sept. 7
    Seeds mature       Oct. 10       Oct. 6        Sept. 27

Mountain muhly flowering times are:

         Arizona              August-September   [46]
         California           June-August        [60]
         Colorado             July-September     [23,68]
         Wyoming              July-September     [23]
         Intermountain West   July-September     [16]

Related categories for Species: Muhlenbergia montana | Mountain Muhly